The Byzantine Empire's disastrous defeat by the Seljuk Turks at Manzikert in 1071 effectively marked the end of what is often described as the 'middle' period of Byzantine history. Thereafter, surrounded on all sides by younger, more vigorous nations, the once all-powerful Empire slipped into a steady decline which, ultimately, was to prove terminal. However, the Empire's demise was anything but peaceful, and, one way or another, for much of the last four centuries of its existence it was to find itself in a state of virtually constant war. This book examines the fascinating history of the Byzantine Empire and its armies from 1118-1461 AD.